The discussants commend the authors technique for deterimining the coefficient of earth pressure at rest (Ko). The procedure allows the separation of elastic and sliding components of deformation. The method however, requires two triaxial tests at different constant stress ratio for the same porosity. In practice this means at least two tests even when the approximate value of Ko is known so that limiting constant stress ratio can be selected. If, for a particular material the approximate Ko value is not known, the method may require a number of tests to select the limiting range of constant stress ratio whereby a correct interpolation can be made. If too wide a range of constant stress ratios is used the validity of the interpolation method is questionable. Several Ko burette tests for granular soils were conducted from coarse sand to medium gravel and consistent results were obtained. However, the method was found to be very time-consuming in the case of fine particles. It is pointed out that the Ko value depends not only on the angle of internal friction, but also on the surface roughness and angularity. Results are presented of tests that suggest that the variation in values of Ko decreases with increasing angularity and grain size. A table is presented which show the percentage variation with respect to the lowest values of initial void ratio, the angle of friction, and the coefficient of earth pressure at rest. The analysis of the author's results for variation in values of Ko is tabulated.

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  • Supplemental Notes:
    • This is a discussion of a paper by Kamal Z. Andrawes and Mohamed A. El-Sohby, July 1973 (Proc. Paper 9863).
  • Corporate Authors:

    American Society of Civil Engineers

    345 East 47th Street
    New York, NY  United States  10017-2398
  • Discussers:
    • Dayal, U
    • Allen, J H
  • Publication Date: 1974-5

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Filing Info

  • Accession Number: 00262727
  • Record Type: Publication
  • Report/Paper Numbers: Proc. Paper 10504
  • Files: TRIS
  • Created Date: Nov 27 1974 12:00AM